Question

The difference between 2 numbers is 18 . If their sum is 86 . What are the numbers ?

Answer 1

let the no. be =x
x-18=86
x=86+18
=104
so x=104

Answer 2

let those numbers a and b
a-b = 18 - eq.1
a+b = 86 - eq. 2


by adding eq.1 with eq. 2
( a-b )(a+b) = 18 +86
2a = 104
a = 52

by putting the value of a in eq. 1
(you can find the answer by putting the value in any of the above equation )
a+b = 86
52 +b =86
b = 86-52
= 34.
so, those numbers are 52 and 34.